Antiarrhythmic and antifibrillatory properties of aprindine. The effectiveness of aprindine, N-[3-(diethyl amino)propyl]-N-phenyl-2-indanamine, was examined against experimentally induced arrhythmias. Ouabain-induced ventricular tachycardia was reversed in six of six dogs by aprindine, 5 mg/kg i.v. The threshold for extrasytoles induced by a 250-msec train of 60 Hz 2-msec pulses starting 75 msec after the pacing pulse was elevated from a control value of 0.18 +/- mA to a peak of 0.29 +/- 0.03 mA 5 minutes after aprindine, 5 mg/kg (P less than .005). The similarly determined ventricular fibrillation threshold was increased from a control value of 2.45 +/- 0.78 mA to a maximum of 5.68 +/- 1.47 mA 30 minutes after aprindine, 5 mg/kg i.v. (P less than .025). Aprindine failed to protect against fibrillation associated with one-stage occlusion and release of the left anterior descending coronary artery. Conscious dogs 24 hours after two-stage ligation of the left anterior descending coronary artery showed ectopic beats averaging 107 +/- 5 beats/min. Aprindine, 5 mg/kg i.v., caused an initial reduction of the ectopic rate to 1 +/- 1 beats/min (P less than .001) returning to 57 +/- 19 beats/min (P less than .05) 30 minutes postdrug. An additional 5 mg/kg dose reduced the ectopic rate to 1 +/- 1 beats/min (P less than .001) returning to 15 +/- 8 beats/min (P less than .005) 60 minutes after drug. Evaluation of these animals at 48 hours showed a similar pattern, although one animal fibrillated after 5 mg/kg of aprindine. Aprindine is an effective antiarrhythmic agent in some experimental cardiac arrhythmias, but the appearance of central nervous system toxicity at therapeutic drug concentrations in conscious animals indicates that it may have a narrow margin of safety.


Pharmacology of a potent, new antithrombotic agent, 6-methyl-1,2,3,5-tetrahydroimidazo[2, 1-b] quinazolin-2-one hydrochloride monohydrate. The effect of 6-methyl-1,2,3,5-tetrahydroimidazo[2,1-b] quinazolin-2-one hydrochloride monohydrate (BL-3459) on platelet function and experimental thrombosis was evaluated in a series of in vitro, ex vivo and in vivo animal experiments. Potent inhibition of platelet aggregation for BL-3459 was demonstrated by both in vitro and ex vivo techniques. In vitro, EC50 levels were less than 1 mug/ml regardless of the aggregating substance used or the species of animal from which platelet-rich plasma was obtained. After oral administration to rats and dogs, BL-3459 was rapidly absorbed and had a long duration of action. Ex vivo ED50 values were in the range of 2 to 3 mg/kg p.o. In addition, BL-3459 (1-10 mg/kg) demonstrated significant oral activity in a variety of in vivo animal models. BL-3459 inhibited elevation in screen filtration pressure induced by hemorrhage in dogs, endotoxemic death in rats, intravascular thrombosis produced by electrical stimulation of the carotid artery of the dog and thrombosis induced by means of a biolaser in the microvasculature of the rabbit ear chamber. In contrast to acetylsalicylic acid, BL-3459 had little effect on bleeding time in guinea pigs. Oral or intraduodenal administration of BL-3459 to dogs lowered aortic blood pressure, stroke volume and peripheral vascular resistance, while elevating cardiac rate and cardiac contractile force. Thus, it had little effect on the estimated cardiac output. These cardiovascular effects were mediated, in large part, through direct-acting mechanisms. BL-3459 exhibited weak antiserotonin activity in isolated smooth muscle preparations. While the precise mechanism of action of BL-3459 has not yet been determined, indications are that the compound may prove useful in the prevention of intravascular thrombosis.


Potassium prorenoate: a new steroidal aldosterone antagonist. Potassium prorenoate (SC-23992) is a water-soluble steroidal compound with the ability to antagonize the sodium-retaining and, when apparent, the potassium-dissipating effects of mineralocorticoids. A significant natriuretic response was obtained at dosages of 1 mg/kg and approximately 1.8 mg/kg in the dog and rat, respectively. Based upon an elevation in the previously depressed urinary log Na/K ratio, prorenoate possesses an oral potency of 4.6 and 8.1 times that of spironolactone (S), respectively, in the aldosterone and deoxycorticosterone acetate-treated adrenalectomized rat. In the aldosterone-treated dog, the compound had 3.0 times the potency of S and 2.2 times that of a related steroid, potassium canrenoate (SC-14266). Prorenoate and S are relatively inactive at the renal level in adrenalectomized rats without mineralocorticoid replacement. Prorenoate possesses no more than 2% of the natriuretic activity of hydrochlorothiazide in the intact animal. Clearance studies in dogs indicate a direct renal tubular site of interaction between prorenoate and aldosterone independent of changes in renal hemodynamics. The natriuretic response occurred within 100 minutes after a single oral dose and was sustained for at least 7 hours. Prorenoate possesses the pharmacological characteristics of an aldosterone antagonist, in common with those of S.


An enzymatic method (phospholipase B) for studies on cestode infection (Hymenolepis nana) and its suppression by chemotherapy. The phospholipase B activity of the small intestine of mice infected with Hymenolepis nana has been studied to determine its value as a laboratory test for the presence of parasites and the chemotherapeutic effects of antitapeworm drugs. Mice infected with 500 H. nana eggs were examined on the 21st day of infection and the phospholipase B content of homogenates of small intestine was determined using lysolecithin (6.6 x 10(-3) M) as the substrate. Some of the infected animals were treated with niclosamide according to schedules and doses known to affect worm development. Presence or absence of parasites was verified by visual inspection of the intestinal content. The enzymatic and visual methods gave equivalent results in both infected-not treated and infected-treated groups. Special features of niclosamide action (relative refractoriness of the early parasitic forms, enhanced effect of multiple doses) have been confirmed. The enzymatic method is proposed as a procedure for laboratory testing in chemotherapeutic investigations.


Hepatic microsomal ethanol-oxidizing system (MEOS): dissociation from reduced nicotinamide adenine dinucleotide phosphate oxidase and possible role of form I of cytochrome P-450. The activity of the hepatic microsomal ethanol-oxidizing system (MEOS) was compared with the content of three forms of cytochrome P-450. Measurements were also made of the activity of microsomal reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, the enzyme which generates H2O2 in microsomes and which has been considered by some to be the rate-limiting step of MEOS activity. Ethanol feeding to rats for 4 to 5 weeks significantly enhanced the activities of MEOS and NADPH oxidase by 102 and 62%, respectively. Concomitantly, form I of cytochrome P-450 was increased by 88% (P less than .001). Acute administration of a large dose of ethanol to animals pretreated chronically with ethanol enhanced MEOS activity by 21% (P less than .05), whereas NADPH oxidase activity remained unchanged. In addition, an acute dose of ethanol enhanced form I of cytochrome P-450 by 20% (P less than .05); thus its increase was comparable to that of MEOS activity. Pretreatment of rats with phenobarbital increased the specific activity of microsomal NADPH oxidase by 40% (P less than .05) but not that of MEOS. By contrast, CCl4 administration to rats diminished MEOS activity by 33% (P less than .01), whereas NADPH oxidase activity remained unchanged. The CCl4 treatment was found to decrease significantly all three forms of cytochrome P-450: form I by 45%, form II by 56% and form III by 24%. These results suggest that in the presence of NADPH microsomes oxidize ethanol to acetaldehyde by a process which involves, at least in part, the form I of cytochrome P-450 and in which H2O2 generation by NADPH oxidase is not the rate-limiting step.


The distribution time of intravenously injected raffinose and inulin in intact animals and the effect thereon of sex and infusion of oxytocin. 1. In anaesthetized dogs whose renal pedicles were ligated the distribution time for I.V. administered raffinose was noted. In males the plasma concentration of raffinose fell for 7-10 min from the time of injection and in females it fell for 12-15 min; thereafter in both sexes the plasma concentration remained constant. 2. During I.V. infusion of oxytocin 10 mug/kg. min, the distribution time for raffinose was 12-16 min in males and 4-6 min in females. 3. During the period before stabilization of plasma concentration the concentration of raffinose was higher in the femoral artery than in the vein in both sexes. 4. In anaesthetized rats whose renal pedicles were ligated the distribution time for I.V. injected inulin was 7-8 min in males and 5 min in females. 5. Following alpha-adrenoceptor blockade with phentolamine the distribution time in both male and female rats was 14-15 min. 6. The sex differences in distribution time, both in normal and oxytocin-treated dogs, may be related to the state of contraction and differential sensitivity or pre- and post-capillary blood vessels and hence, of capillary pressure.


The detection of gratings by independent activation of line detectors. 1. The visibility of composite stimuli (double lines, multiple lines and sinusoidal gratings) is analysed in terms of the visibility of single lines. 2. The detection mechanisms for the composite stimuli were examined by measuring the probabilities for seeing these stimuli, the probabilites of "recognition" near their detection thresholds and by using the method of subthreshold summation. 3. The simplest composite stimulus consists of two lines spaced apart by 15 min; it was found that both the probability of seeing this stimulus and the probability of reporting either one or two lines may largely be explained by assuming independent detection of the two lines. For a 12 min spacing some antagonistic interaction was observed between the two lines, confirming the existence of an antagonistic surround in the line detector. 4. The probability of seeing a multiple line target (rectangular grating) of spacing 15 min is slightly greater than that predicted assuming independent detection of its component lines; this probability can be calculated from the probabilities of seeing a central line (near the fixation point) and pairs of lines spaced 15, 30, 45, 60, 75 and 90 min on either side of the fixation point. The observed threshold for the grating was about 0.05 log units less than the prediction. 5. The probability that a subject reports only one line from a rectangular grating was found to be consistent with independent detection of its component lines when the subject used a low (detection) threshold criterion but not for higher criteria. 6. The spatial frequencies involved in the detection of the rectangular grating were determined by subthreshold summation; the high spatial frequency selectivity was shown to be consistent with independent detection of the component lines. 7. The detection mechanism for a 4 c/deg sinusoidal grating was found to be similar to that for the 15 min rectangular grating. 8. Evidence is presented that the detection of finer and coarser gratings may be analysed in similar terms. 9. It is shown that lines are not detected by independent activation of sharply tuned grating detectors but that sub-units may be involved which are slightly more narrowly tuned than the line detector. 10. These sub-units contain both inhibitory and disinhibitory regions; the disinhibitory responses may be the basis of the deviations from probability summation noted  in 4. 11. The properties of the proposed sub-units are in reasonable accord with the results of adaptation experiments.


Insulin-stimulated entry of glucose into muscle in vivo as a major factor in the regulation of blood glucose. 1. The entry of glucose into the pectoralis major muscle of living rats was measured over a wide range of plasma glucose concentrations. A technique was used by which steady concentrations of substances are maintained in the circulation throughout the experiments. 2. Raising the concentration of glucose in the plasma caused saturation of the mechanism by which it is transported into muscle. Estimates of the values of the kinetic constants for this transport system were: Kt, 34 mumole ml-1 and V, 1-2 mumole min-1-g-1 muscle. 3. When the plasma glucose concentration was raised up to at least twelve times normal, there was no sign of saturation of the transport system in insulin-treated animals. This finding could be explained if insulin increased greatly both V and Kt for glucose transport. 4. Insulin increased the rate of entry of glucose into muscle over the entire range of plasma glucose concentrations studied (4-8 mumole ml.-1). There was evidence that endogenous insulin produced a similar increase in entry rate some 10 min after the injection of glucose. Fasting, which is associated with a decrease in insulin level, depressed the rate of entry. In hyperglycaemia insulin caused a rise in the concentration of glucose within the muscle cells. 5. The insulin-induced increase in the rate of glucose entry into muscle ensured that approximately 25% of an I.V. dose of glucose entered the muscle cells of insulin-treated animals within one minute. This illustrates the quantitatively important regulatory role that skeletal muscle plays in these circumstances in limiting the extent of a rise in circulating glucose.


Effects of nerve growth factors from mouse salivary glands and snake venom on the sympathetic ganglia of neonatal and developing mice. 1. Quantitative histological analysis has been made of the effects of nerve growth factor (NGF) from mouse submaxillary gland and from the venom of Vipera russelli on superior cervical ganglia of neonatal mice. 2. The hypertrophic and hyperplastic effects reported by other workers have been confirmed. 3. The hypertrophic effect arises from an increase in the rate at which the sympathetic neurones attain their mature size. The size at maturity is never exceeded. 4. The hyperplastic effect arises from an increase in the rate of production of neurones from less differentiated cells. In the developmental period, the number of neurones can exceed that found at maturity. If injection of NGF is discontinued the excess neurones disappear. 5. If injection of NGF is continued to maturity, the excess number of neurones is maintained.


Multiple interneuronal afferents to the giant cells in Aplysia. 1. Several different types of presynaptic neurones to the giant cells of Aplysia have been found in the pleural ganglion. Some of these presynaptic neurones are common to the left giant cell in the pleural ganglion and to the right giant cell in the abdominal ganglion but others make contact only with one. 2. Interneurones of the left giant cell were studied in detail. They can be identified not only physiologically from the type of post-synapitc potential (p.s.p.) which they produce in the left giant cell, but also by their localization in the ganglion. 3. Direct stimulation of these presynaptic neurones produced not only the classical types of post-synaptic potentials known as e.p.s.p. or i.p.s.p. but also a slow e.p.s.p. and more complex post-synaptic potentials consisting of a rapid depolarizing or hyperpolarizing component (e for excitatory; i for inhibitory). According the p.s.p.s. which have been found were classified as being of eight different types: e.p.s.p., slow e.p.s.p., pseudo-slow e.p.s.p., e.i.p.s.p., i.e.p.s.p., i.i.p.s.p., to which is added the biphasic p.s.p. (b.p.s.p.) of electrical origin. 4. The monosynaptic nature of each of these p.s.p.s. was established by four criteria: (a) ability to follow one to one the presynaptic spike, (b) short and constant latency, (c) change of p.s.p. with the presynaptic spike when the duration is prolonged by iontophoretic injection of TEA, (d) sensitivity of the synaptic efficacy to presynaptic polarization. 5. For all p.s.p.s., the hyperpolarization of the interneurone was followed by a decrease in the corresponding amplitude; on the contrary depolarization produced an increase in p.s.p. amplitude. 6. The physiological role of these p.s.p.s. and their possible mechanism are discussed.


Intracellular recordings of rod responses during dark-adaptation. 1. Dark-adaptation of rod photoreceptors has been studied in the isolated axolotl (Ambystoma mexicanum) retina by intracellular recordings. Rod responsiveness was greatly reduced immediately after a 30 sec partial bleach, but partially recovered with time in the dark. 2. In parallel spectrophotometric measurements using isolated retinas, regeneration of the rod pigment could not be detected after a 30 sec bleach. 3. During rod dark-adaptation, the response of a rod to a given stimulus increased in amplitude, duration, and rate of rise but did not recover completely to the dark-adapted values. Response latency was lengthened immediately after a bleach but ultimately returned to the dark-adapted level. 4. The time courses of dark-adaptation determined on the basis of the intensity of a stimulus needed to evoke a response having a criterion amplitude, a criterion duration, or a criterion rate of rise were similar. On the other hand changes in latency of the response and magnitude of the saturated amplitude followed different time courses. Change in log threshold was found to be related to change in saturated amplitude by an exponential function during dark-adaptation. 5. After bleaching 10% or less of the rod pigment, the kinetics of both recovery of log threshold and decrease in absorbance at 400 nm (metarhodopsin II+free retinal) could be described by two concurrent first-order processes having similar time constants. However, after bleaching more than 10% of the rod pigment, changes in sensitivity and absorbance did not follow parallel time courses. 6. Metarhodopsin III cannot be solely responsible for setting the axolotl rod sensitivity since rod thresholds decrease monotonically during dark-adaptation whereas meta III concentration reaches a peak 3 min after the bleach and decreases thereafter.


Acetylcholine responses on clonal myogenic cells in vitro. 1. Some electrophysiological properties of the acetylcholine response shown by clonal rat myogenic cells were studied in vitro. Some mononucleate myoblasts showed a slow hyperpolarizing response. 2. Multinucleate myotubes showed a fast depolarizing response that was very similar to that of mammalian skeletal muscle in vivo, and differed from the hyperpolarizing response of myoblasts. 3. The depolarizing response involved Na, K and Ca ions, but not Cl ions. The dependence of the reversal potential on external ion concentrations was generally similar to that shown by frog muscle, but some quantitative differences were seen. 4. The reversal potential determined at sites of nerve-muscle interaction did not differ from those at background or non-interacted sites.


The effect of calcium ions on the binomial statistic parameters which control acetylcholine release at synapses in striated muscle. A study has been made of the effects of changing [Ca]O and [Mg]O on the binomial statistic parameters p and n which control the average quantal content (m) of the synaptic potential due to acetylcholine release. 2. When [Ca]O was varied in the range 0-1 to 1-0 mM, p increased as the first power of [Ca]O whereas n increased as the third power of [Ca]O. 3. Increasing [Mg]O depressed both p and n, however variations of [Ca]O in the presence of high [Mg]O did not significantly change the power relationship between either p and [Ca]O or between n and [Ca]O. 4. The facilitated increase in m during a short train was due to an increase in n, whereas the post-tetanic increase in m during a tetanus was due to an increase in p. These results are considered in terms of the role of Ca ions in facilitation and post-tetanic potentiation.


Responses of inner and outer muscle of the sheep carotid artery to injury. 1. Direct injury to the smooth muscle of the sheep carotid artery in vivo caused large, persistent and sharply limited annular contraction, even with tetrodotoxin 10(-5)M present to block nerves. 2. Surcose gap records from artery strips showed that mechanical injury caused slow, prolonged depolarization of the smooth muscle that spread for a few millimetres in a circular direction in relation to the intact artery wall with an apparent space constant of 1-26--3.49 mm. In the longitudinal direction, no depolarization was recorded 1 mm from the site of injury. No spikes were recorded more than 1 mm in either direction from the site of injury except when procaine, which facilitates electrical activity in the smooth muscle, was present. 3. When responses of inner and outer muscle were recorded separately, injury caused comparable contraction of both parts. 4. Clotted blood caused large contractions of intact artery strips; it contracted inner much more than outer muscle. 5. The main factors in the intact vessel's response to injury therefore seem to be inner and outer muscles' direct response to injury, reinforced by spread of depolarization round the vessel wall, and inner muscle's response to vasoconstrictor agents released by clotting blood.


The ionic dependence of action potentials induced by colchicine in an insect motoneurone cell body. 1. The ionic requirements of the action potential recorded in the cell of an identified cockroach (Periplaneta americana) motoneurone following pre-treatment of the animal with colchicine have been studied. 2. Small cubes of gelatin containing 1% colchicine were implanted into one metathoracic leg near to the nerve trunk containing the axon of the identified motoneurone. 3. Electrophysiological experiments were performed 4--10 days after this treatment, when action potentials which frequently overshoot zero potential can be recorded from the cell body. Such action potentials are not normally seen in untreated animals. 4. Sodium-free solution reversibly abolished the action potential within 5 min. 5. Tetrodotoxin (10(-8)M) reversibly depressed the action potential. It was totally abolished by 10(-7)M tetrodotoxin, but this effect was not reversible. 6. Saline solution containing 40 mM manganous chloride either had no effect on the action potential amplitude, or caused a slight increase. It also caused prolongation of the falling phase and loss of the after-hyperpolarization. These effects were all reversible. 7. It is concluded that sodium carries a major proportion of the inward current of the action potential in this neurone. Some calcium probably enters also, and may, at least in part, be responsible for triggering the delayed rise in potassium conductance during the action potential.


Sensitivity of central chemoreceptors controlling blood glucose and body temperature during glucose deprivation. 1. The rise in blood glucose and the fall in body temperature which follows the injection of a glucose analogue, 2-deoxy-D-glucose (2-DG) into the lateral cerebral ventricle (I.C.V) of unanaesthetized rats were studied and found to be dose-dependent. These 2-DG induced responses are elicited by the impairment of glucose metabolism within central "glucoreceptors'. 2. 2DG induced hyperglycaemia and hypothermia were completely prevented and even the converse effects occurred when fivefold equimolar amounts of D-fructose were simultaneously injected I.C.V.; fructose, at equimolar doses, did not modify the effects of 2-DG. 3. D-xylose and D-ribose, even at high doses, did not influence 2-DG hyperglycaemia, but increased slightly the 2-DG induced hypothermia. This suggests that the pentose phosphate pathway is unable to support the metabolism within the glucoreceptors. 4. Pyruvate suppressed the 2-DG induced hyperglycaemia with a marked delay, while acetate (as ethyl ester) and a mixture of malate plus oxaloacetate did not prevent 2-DG induced effects. These results may be accounted for by the low dosage used. 5. Acetoacetate and 3-hydroxybutyrate did not prevent 2-DG hypothermia and hyperglycaemia. 6. An effective prevention of the 2-DG induced hyperglycaemia and hypothermia was achieved with fumarate and glutamate, indicating that the stimulation of the Krebs cycle within "glucoreceptors' removes the glucoprivic effects. 7. The results indicate that prevention of 2-DG induced effects occurred only with alternate source of metabolic fuel which can support high respiratory rates in brain tissue. It is concluded that central chemoreceptors are not specifically responsive to glucose, or hexoses, but to the rate of oxidative metabolism.


Preparation and partial characterization of hepatic regenerative stimulator substance (SS) from rat liver. 1. The elucidation of the biochemical controls of growth processes is basic to understanding both normal and malignant growth. The exquisitely sensitive control demonstrated in the regenerating liver provides an excellent model system for growth studies. 2. Intraperitoneal injection of an extract from weanling rat liver into 34% hepatectomized rats stimulates [3H]thymidine incorporation into recipient hepatic DNA 2.5-fold. This stimulation is seen after a 10 hr lag period. 3. Extracts from weanling rat liver contain the highest level of the hepatic regenerative stimulator substance (SS), whereas extracts from adult liver give no significant stimulation. 4. If adult rats are partially hepatectomized, SS is demonstrated in their livers 12-15 hr after hepatectomy. 5. Partial characterization of SS shows that it is a soluble material not sedimented by centrifugation for 2 hr at 145,000 g. The stimulator activity is stable to heating at 65 degrees C and 100 degrees C for 15 min but is lost when treated with 10% perchloric acid.


Properties of centre-hyperpolarizing, red-sensitive bipolar cells in the turtle retina. 1. Responses of centre-hyperpolarizing, red-sensitive bipolar cells were studied by intracellular recording in the retina of the turtle, Pseudemys scripta elegans. The identity of these cells was confirmed by Procion Yellow marking. 2. Circles of light produced hyperpolarizing waves that were graded with intensity and could exceed -30mV in amplitude. The operating intensity range was similar to that of turtle cones. 3. Flashes in the form of an annulus evoked graded depolarizations which could be greater than 10 mV in the dark-adapted state or about 30mV when applied over central backgrounds. 4. Responses proportional to intensity were produced by dim circular stimuli. For radii less than about 200 mum these responses reached peak in approximately 120 msec and were invariant with respect to wave-length or area of illumination. Absolute flash sensitivity varied greatly from cell to cell but in the most sensitive cell encountered was about 460 muV photon(-1) um2. 5. Sensitivity of both bipolar cells and red-sensitive cones was enhanced progressively for enlargements of a circular flash up to 150-200 mum in radius. 6. Increasing the radius of a circle from 200 to 1250 mum caused a decrease of about 75% in bipolar cell sensitivity. This decrease was associated with a marked shortening of the response for all colours. The same enlargement decreased sensitivity of red-sensitive cones by approximately 20% and did not appreciably alter the time course of their response. These effects are attributed to impingement from type I  red-sensitive horizontal cells because they have the requisite spatial and spectral properties. 7. Responses of a few bipolar cells were already shortened for 200 mum flashes; this property suggests impingement from type II horizontal cells. 8. For small circles the spectral sensitivity of the bipolar cells considered resembled closely that of red-sensitive cones or horizontal cells. Red backgrounds enhanced the relative sensitivity to green flashes suggesting that these bipolar cells receive input from red-sensitive members of double cones as well as single red-sensitive cones. 9. Steady depolarizing currents injected into bipolar cells decreased the response to either central or annular illumination; hyperpolarizing currents decreased the response to a central flash and increased the response to an annulus.


Sugar absorption by foetal and neonatal rat intestine in vitro. 1. Sugar absorption by foetal and neonatal rat intestine has been examined using an in vitro accumulation technique. 2. The capacity for active sugar absorption is present in the rat intestine by the 17th day of gestation. Considerable variation in uptake occurs during the first month post partum; the greatest uptake place during the first week. 3. The absorption of sugars by the developing gut resembles in several respects that by the mature intestine. However, the adult pattern of functional localization along the intestine is not fully established until after the 3rd week post partum. 4. Kinetic studies indicate that variations with age in the distribution of sugar "carriers' along the intestine, rather than changes in the "carriers' themselves, account for the observed variations in absorption.


Thermal receptors in the scrotum of the rat. 1. The technique of single fibre dissection has been used to study the warm and cold thermoreceptors in the rat scrotum. 2. The warm receptors showed dynamic activity during increases of scrotal temperature and static activity when temperature was constant. The static activity/temperature curve was bell-shaped, with minima at 31 and 45 degrees C and a peak at 42 degrees C. 3. The cold receptors also showed dynamic and static responses to reductions of temperature. At steady temperatures the impulses from some receptors were grouped in bursts. The number of impulses in each burst increased from zero at 30 degrees C to four at 20 degrees C.


Convergence in a thermal afferent pathway in the rat. 1. In anaesthetized rats, unit activity was recorded in the afferent somatosensory pathway leading from the scrotum. Recording sites were in the dorsal horn near the entry zone of the scrotal nerve, in the ventrobasal complex of the thalamus and in the somatosensory (SI) cortex. During recording, the temperatures of the left and right sides of the scrotum were varied independently. 2. Almost all (64/67) the units in dorsal horn, thalamus and cortex responding specifically to scrotal temperature were equally affected by temperature changes on either side of the scrotum. The receptive fields of these units were bilateral and large, implying a massive convergence of fibres from thermoreceptors on to each central unit. In contrast, mechanosensitive units responded only to unilateral stimulation. 3. As a consequence of the convergence in the thermal pathway, the firing rate of each central unit was a function of an additive combination, often simply the sum, of the temperatures of the two sides of the scrotum. 4. The relationship between firing rate and the temperature of one side of the scrotum was sigmoid, the position, but not the shape, of the curve depending on the temperature at which the opposite side was maintained. An increase in the maintained temperature shifted the sigmoid response curve towards lower temperatures and vice versa. 5. The convergence which this pathway exhibits would be well suited to integration of the temperature of the scrotal skin, but not to spatial discrimination.


The effect of duodenal infusion on the electromyogram of gastric muscle during activation and inhibition of gastric emptying. 1. When the abomasum of the conscious calf is partially distended, rhythmic motility can readily be recorded from the e.m.g. of the smooth muscle of the fundus (body) and antrum. 2. In gastric evacuation rhythmic contractions of the antrum are reinforced by both rhythmic and tonic fundic contractions. 3. The output volume of the stomach can be directly correlated with e.m.g. activity. 4. Intragastric fluid is usually emptied in gushes coinciding with a strong contraction of the antrum but fluid may be evacuated, when the antrum is inactive, through the force generated by persisting rhythmic fundic contractions. 5. Using re-entrant cannulae so that the duodenum can be infused separately from the gastric effluent, isotonic sodium bicarbonate produced almost 100% gastric evacuation with greatly enhanced e.m.g. activity of fundus and antrum. Infusion of the duodenum with a solution of HCl, 60 m-equiv/l., produced the opposite effect, the gastric muscle becoming quiescent and 100% of the gastric test meal being retained. 6. These results show that the activating or inhibitory effects of a duodenal infusate are produced through an activating or inhibitory effect on the smooth muscle of the stomach. 7. The mechanism of the interrelation between duodenal receptor and gastric effector has not yet been elucidated but the connexion is not intramural since it continues when the duodenum is transected near to the pylorus.


Rhodopsin flash photolysis in man.

Rhodopsin flash photolysis in man. 1. Human rhodopsin in vivo was flash bleached by a 600 musec xenon flash which could deliver to the retina up to 15 rod-equivalent quanta per rhodopsin molecule, and the fraction bleached measured by fundus reflexion densitometry. 2. The curve relating fraction rhodopsin bleached to intensity of flash saturates at 0.5 to 0.6. Thus, 40-50% of the rhodopsin is left photo-regenerated by the brightest flashes. 3. Three types of densitometry experiments confirm the saturation of the bleaching curve. 4. The kinetic constants required to account for the observed photo-regeneration were somewhat discrepant with in vitro and in situ estimates from infrahuman species. Specifically, (i) the quantum efficiency of the back reaction, metarhodopsin I hv leads to rhodopsin, was inferred to be nearly as high as that of the forward reaction; and (ii) the rate of the metarhodopsin I leads to metarhodopsin II dark reaction was inferred to be less than 500 sec(-1).


Rushton's paradox: rod dark adaptation after flash photolysis. 1. Rod dark adaptations after a photoregenerating flash and quantum-equivalent 30 sec bleach are found to be in exact agreement, while the measured rhodopsin regenerations are grossly different. This finding confirms and clarifies "Rushton's paradox', the failure of the Dowling-Rushton equation (linking log sensitivity linearly with unregenerated rhodopsin) to account for human rod dark adaptation after flash photolysis. 2. The hypothesis that the agreement between rod dark adaptation curves after a photoregenerating flash and after a quantum-equivalent 30 sec bleach is coincidental is rejected on the basic of two classes of experiments. 3. Rod "bleaching' adaptation is demonstrated to be entirely determined by the number of rhodopsin molecules which absorb at least one quantum in a temporal period T, whose range includes the time interval 600 musec less than or equal T less than or equal 30 sec. This generalization obtains over the entire scotopic energy range (congruent to 3 log units) where rod dark adaptations has been studied. 4. Thus, the state of "bleaching' adaptation is determined by some by-product of the normal chain of events in scotopic excitation. About this by-product three important deductions are made: (i) its production is a monotonic function of the initial effective quantum absorptions; (ii) its production occurs before the metarhodopsin I leads to to metarhodopsin II dark reaction; (iii) it cannot be any photoproduct of the rhodopsin cycle.


Light path and photon capture in turtle photoreceptors. 1. The directional selectivity of individual cones was examined by intracellular recording in the eye of the turtle. Sensitivites were determined from linear responses to dim flashes of monochromatic light incident on a cell over a range of angles to its long axis. 2. With light near the optimum wave-length, some red- and green-sensitive cones showed a high sensitivity for light entering axially and lower sensitivities for light entering obliquely. In contrast, other cells had lower peak sensitivities and less pronounced directional selectivities. The highest axial sensitivities observed in red receptors were about 320 muV photon(-1) mu2; in these cells, the sensitivity declined to half for rays 6-9 degrees off the axis as measured in the retina. Green receptors had lower axial sensitivities and broader angular profiles. 3. On the assumption that rays at all angles contribute independently to the over-all sensitivity, the sensitivity of a cell to large cones of rays was successfully predicted from the angular selectivity determined with a narrow pencil of rays. The shape of small responses to dim stimuli delivered on and off the axis of the cell was invariant, implying that a cone signals the number of photons absorbed but not their angle of incidence. 4. Short wave-lengths have previously been shown to be filtered out by the oil droplets present in turtle cones. At short wave-lengths, the angular profiles showed a depression in axial sensitivity consistent with this filtering action. 5. Diameters of inner segments, oil droplets, and outer segments were measured in red-, green-, and blue-sensitive cones, since these dimensions are expected to influence the cones' angular acceptances and ability to collect light. The diameters of the structure were in approximately the same proportions for each type of receptor, but the absolute values of the diameters were found to be scaled in relation to the wave-length of maximum sensitivity. 6. Optical determinations of the efficiency with which axial rays are concentrated by red receptors gave a mean value of 55%. 7. Receptors in histological sections of the whole eye were found to be oriented with their long axes directed approximately toward the pupil. 8. The observed directional selectivities and collecting efficiencies agree well with the behaviour of a model retinal cone developed by Winston & Enoch (1971) on a geometrical optical treatment. 9. Effective collecting areas are derived for red-, green- and blue-sensitive cones; these permit conversion of observed flash sensitivities into the mean peak hyperpolarization produced by isomerization of a visual pigment molecule. The figure obtained is about 25 muV for red-sensitive cones and 21muV for green-sensitive cones.


Sensorimotor cortical representation in the rat and the role of the cortex in the production of sensory myoclonic jerks. 1. After administration of 1,2-dihydroxybenzene (catechol) to anaesthetized rats, rabbits and cats, a reflex jerk consisting of three distinct components was evoked in the limb muscles by peripheral stimulation. The second component of the jerk in the forelimb muscles of all three animals was specifically abolished by lesions confined to the contralateral forelimb sensorimotor cortex. 2. These lesions had no effect on the second response in either the hind limbs or in the forelimb ipsilateral to the lesion. The first and third responses were also unaffected. 3. Lesions in the cat hind-limb cortex abolished the contralateral hind-limb second response, but not the ipsilateral hind-limb or forelimb response. 4. In the rat and rabbit, unilateral hind-limb sensorimotor lesions were ineffective in completely abolishing the second response in the contralateral hind-leg muscles, and in addition, reduced the probability of occurrence of the response in the ipsilateral hind leg. Bilateral lesions abolished the response. 5. Re-investigation of the sensory and motor representation of the hind limb in the rat cortex revealed that this is bilateral in nature. Short-latency cortical responses (ca. 7-0 msec) could be evoked in one cortex by stimulation of either hind paw. The geometric centre of the cortical area from which these responses could be recorded was identical for each hind paw. 6. After catechol injection, stimulation of the cortical surface with single anodal shocks of threshold strength produced responses at similar latency (ca. 8-0 msec) in both hind limbs. 7. The behaviour of the second response after cortical lesions corresponds closely with the pattern of the somatosensorimotor cortical representation. The latency of the response is such as to allow its production by a long-loop cortical reflex, and this possibility is discussed.


Responses of tendon organs in a lizard.

Responses of tendon organs in a lizard. 1. In the lizard Tiliqua the tendons of the caudo-femoralis muscle are supplied by a nerve which runs separately from the muscle nerve. 2. Recordings of afferent discharges in the tendon nerve revealed the presence in the tendon of stretch-sensitive mechanoreceptors which responded to both passive changes in limb position and to muscle contraction. 3. A preparation of the tendon and its nerve were dissected free of surrounding tissue and studied in isolation while recording the activity of single functional units. The minimum tension in the tendon necessary for a maintained response from a receptor lay in the range 5-35 g (mean 16 g) and the firing rates at these tensions were in the range 5-14 impulses/sec (mean 9 impulses/sec). 4. Receptors showed a steep increase in firing rate with increase in tension up to about 120 g. The firing rate 30 sec after the onset of a tension change did not exceed 40 impulses/sec. 5. During the tension change the receptor responded with a burst of impulses whose frequency depended on the velocity of stretch. With large, rapidly rising tension steps peak firing rates of up to 300 impulses/sec were observed. 6. Tension and length changes recorded during rapid tendon-stretches were very similar, with little sag in tension at the new length. The response of all units however continued to fall throughout the stretch. Some of the possible causes of this adaptation have been discussed.


Effects of afferent volleys from the limbs on the discharge patterns of interpositus neurones in cats anaesthetized with alpha-chloralose. 1. In cats anaesthetized with alpha-chloralose, micro-electrodes have been used to record the discharge patterns of single neurones in the region of the nucleus interpositus. 2. Almost all cells tested could be antidromically invaded following electrical stimulation of the contralateral red nucleus, showing that they were cerebellar efferent neurones. 3. A little over half of the interpositus neurones were spontaneously active, usually at rates of less than 20 impulses/sec. 4. About 40% of the cells had no spontaneous activity, although they gave brisk responses to electrical stimulation of cutaneous nerves. Such silent units were encountered most frequently in the earlier stages of an experiment, but a number were found more than 15 hr after the beginning of an experiment. 5. Stimulation of cutaneous and mixed nerves of the fore and hind limbs provoked impulse discharges of the cells and also produced phases of deceleration of the resting discharge of spontaneously firing cells. 6. The typical response of an interpositus neurone consisted of a short latency (6-35 msec) discharge, usually separated from a long latency (50-500 msec) discharge by a period of inhibition or return to the resting discharge rate. The two phases of excitation appeared to be independently generated, since in a number of cells one phase appeared without the other. In addition, the later phase of excitation was abolished in all cells tested by a small dose of pentobarbitone which produced very little effect on the earlier phase. The long latency response was quantitatively much greater, sometimes consisting of 50 or more impulses in a response which lasted several hundred msec, but was very variable from one trial to another. 7. The long latency discharge and sometimes the preceding inhibition could readily be mimicked by single shock stimulation of the region of the contralateral inferior olive. Short latency discharges were, however, rarely evoked by olivary stimulation. 8. It is suggested that the short latency responses of the interpositus neurones were a result of synaptic excitation via cerebellar afferents, while the ensuing inhibition was a result of post-synaptic inhibition resulting from the Purkinje cell excitation due to the afferent volleys. It is suggested that the long latency excitation is due to the afferent volleys. It is suggested that the long latency excitation is due at least in part to disinhibition resulting from long pauses in Purkinje cell firing following their activation by climbing fibre afferents. 9. The possibility that these long latency responses have a physiological significance in relation to locomotion is discussed.


The turnover of phosphorus compounds in crab muscle fibres. 1. The exchange of 32P injected into single crab muscle fibres as either orthophosphate or ATP has been studied. The results have been analysed in terms of a simple kinetic model. 2. The exchange of 32P between ATP and arginine phosphate is considerably faster than that between ATP and orthophosphate during rest and during contraction in caffeine. 3. The rate constants obtained at rest after the injection of either orthophosphate or ATP labelled with 32P were of the same order. They were also of the same order as those which have been obtained previously for squid axons. 4. The exchange during caffeine contraction of 32P unjected as orthophosphate gave rate constants which were consistent with an increased rate of splitting of ATP and with the rate constants needed to account for the observed net formation of orthophosphate. The results obtained after the injection of 32P-labelled ATP during caffeine contraction were less clear cut.


Absorption of two proline containing peptides by rat small intestine in vivo. 1. Glycyl-L-proline and L-prolyl-glycine are two dipeptides that are poorly hydrolysed by brush border peptide hydrolases in vitro. The present study was undertaken to investigate in vivo intestinal absorption of the two dipeptides in male Wistar rats. A steady-state perfusion technique has been used and jejunal and ileal absorption studied by comparing rates of absorption of constituent amino acids from dipeptide and equivalent equimolar amino acid solutions. 2. Glycine and proline were absorbed at the same or faster rates during perfusion of 10 mM glycyl-L-proline than during perfusion of 10 mM-L-prolyl-glycine than during perfusion of its equivalent equimolar amino acid solution. Conversely, the two constituent amino acids were absorbed at slower rates during perfusion of its equivalent amino acid solution. As expected very low concentrations of free amino acids were detected during the jejunal dipeptide perfusions but higher concentrations were detected during the ileal perfusions. 3. The addition of 40 mM L-prolyl-glycine to the 10 mM glycyl-L-proline solution did not affect the rates of disappearance of glycyl-L-proline. The addition of 40 mM glycyl-L-proline to 10 mM L-prolyl-glycine however had a significant inhibitory effect on the disappearance of L-prolyl-glycine. It is concluded that the two dipeptides may be absorbed by different peptide transport systems.


Physiological identification of a morphological class of cat retinal ganglion cells. 1. Small selected patches of retina (approximately 1 mm2) were exhaustively searched electrophysiologically to identify every brisk-transient unit present. The patches were then marked by electrolytic lesions. 2. Whole-mount preparations were made from which the distribution of alpha cells within and around the marked areas could be obtained. 3. A one-to-one correspondence could be demonstrated between brisk-transient units and alpha cells. 4. The correspondence was maintained within a patch of retina including the central area. 5. The correspondences were subject to about 10% of uncertainty attributed to technical limitations of the method.


Plasma catecholamines in foetal and adult sheep. 1. Foetal and maternal plasma catecholamine concentrations were measured during and after hypoxia (mean maternal Pa,02 44mmHg) in chronically catheterized sheep, 118-141 days pregnant. 2. In most foetuses the initial plasma catecholamines were smaller than 0.07 ng/ml. During hypoxia plasma adrenaline and noradrenaline always rose; there was a rise in arterial pressure and a fall in heart rate. 3. The initial catecholamine concentration in the ewes was smaller than 0.05-2.3 ng/ml. During hypoxia there was no consistent change; the maternal plasma concentrations were less than the foetal. 4. Infusion of adrenaline at 0.3 mug kg(-1) min(-1) to the ewe resulted in plasma catecholamine concentrations higher than those observed during hypoxia. There was a rise in heart rate but no consistent change in arterial pressure. 5. Infusion of adrenaline 0.4 mug kg(-1) min(-1) into the foetal jugular vein caused a rise in plasma concentration similar to that seen during hypoxia. There was a rise in heart rate but no significant change in arterial pressure. 6. The half-life of adrenaline and of noradrenaline in the maternal and foetal circulation was 0.25-1 min. There was no evidence of transfer of labelled catecholamine across the placenta.


Intracellular potentials in cells of the seminiferous tubules of rats. 1. Membrane potentials have been recorded from cells of seminiferous tubules of rats in vitro using micro-electrodes. The value in 808 impalements was -28-2 +/- 0-3 mV (mean +/- S.E.) at 33 degrees C. 2. Increasing the potassium concentration depolarized the cells, a tenfold increase in concentration causing a depolarization of 16 mV. Removal of sodium from the bathing solution caused a hyperpolarization of 3 mV at a potassium concentration of 5-9 m-equiv/l. Removal of chloride and replacement with impermeant anions had no effect on potential. Removal of calcium from the bathing solution caused a minor but significant depolarization. 3. Ouabain (10-3 M), dinitrophenol (2-5 times 10-4 M) or removal of glucose from the bathing fluid all caused depolarization. The membrane potentials of the cells were sensitive to temperature over the range 10-33 degrees C, the apparent activation energy for the reactions maintaining the potential being approximately 6 kcal/mole. 4. Membrane potentials in seminiferous tubules were independent of age of the animal, were insensitive to previous hypophysectomy and were insensitive to a number of hormones (FSH, LH, HCG, oxytocin). In high concentration prostaglandin E1 caused depolarization. 5. Acetazoleamide (4 times 10-5 M) caused a rapid, but reversible, depolarization of the tubular cells. This was also true in conditions when the HCO'3/CO2 buffer system was replaced with Tris-buffer. Another carbonic anhydrase inhibitor (p-sulphonamido-benzoic acid) had similar effects on cell potentials as acetazoleamide. These results are discussed in relation to the nature of the ionic secretion produced in the tubules. 6. Occasional cells showed phasic variations in membrane potential. A possible connexion between these variations and the contractile activity of the tubules is discussed.


Structural, mechanical and myothermic properties of rabbit rectococcygeus muscle. 1. The fine structure of rabbit rectococcygeus muscle has been studied with the electron microscope. 2. The mechanical performance and the heat production of this muscle has been investigated during tetanic contractions at 27 degrees C. 3. In isometric contractions a force of 164 +/- 27 mN/mm2 (mean +/- S.D., n = 17) is developed and the heat production is linearly related to the force. 4. There is a relationship between the duration of stimulation (t) and the total heat production (H) of the type H = A plus bt, where A and b are constants. 5. After-loaded isotonic experiments show that the relationship between force and velocity can be fitted by the 'characteristic equation' of Hill (1938). 6. The value of a/P0 (0-302 +/- 0-093, mean +/- S.D.) is slightly higher than in frog skeletal muscle but the constant b is about 50 times smaller. 7. The ratio of work/total energy production, for the stimulus conditions employed, was maximally 0-185. 8. The ratio of total enthalpy to initial enthalpy is difficult to measure accurately but is probably about 2.


Polyphasic synaptic potentials in the ganglion of the mollusc, Navanax. 1. Included in the ensemble of synaptic input received by identified neurones in the ganglion of the marine mollusc Navanax  are biphasic synaptic potentials, consisting of a depolarization followed by a hyperpolarization. 2. Both phases are chemically mediated as judged by their susceptibility to a high magnesium medium and neither exhibits depression with repetition. 3. The hyperpolarizing phase has a reversal potential of about -50mV, which varies only with changes in the external chloride concentration. This phase is unaffected by cholinolytics. 4. The depolarizing phase reverses at a more positive potential, is probably the result of a change in sodium conductance and is blocked by hexamethonium and high concentrations of eserine. 5. The biphasic synaptic potentials are therefore similar in many respects to the biphasic response evoked by iontophoretic application of acetylcholine on to these cells, suggesting that the two types of cholinergic receptors previously characterized on these neurones are both functional.


Potassium and sodium ion current noise in the membrane of the squid giant axon. 1. The spectral density of current noise power from 20 mm segments of giant axons of the squid Loligo vulgaris has been measured under space-clamp and voltage-clamp conditions. From 4 to 1000 Hz the measured noise is larger by several orders of magnitude than the theoretical thermal noise. The amplifier's noise, which may yield appreciable contributions above 200 Hz, could be evaluated and subtracted from the total noise using direct measurements of the membrane impedance...


Dynamic properties of fast and slow skeletal muscles in the cat and rat following cross-reinnervation. 1. Cross-reinnervation was performed between the slow-twitch soleus (SOL) and fast-twitch extensor digitorum longus (EDL) muscles in the cat and the SOL and fast-twitch flexor hallucis longus (FHL) muscles in the rat. The isometric and force-velocity properties of the muscles were subsequently determined. 2. As a result of cross-reinnervation the dynamic properties of both slow- and fast-twitch muscles in the cat were considerably altered. The isometric twitch time to peak was 33-9 msec in the X-SOL compared with 84-7 msec in the N-SOL. The intrinsic speed of shortening and a/P0 values were 25-4 mum. sec-1 and 0-34 respectively in the X-SOL and 14-4 mum. sec-1 and 0-20 in the N-SOL. In the X-EDL the twitch time to peak was 52-6 msec compared with 23-4 msec in the N-EDL; the intrinsic speed of shortening and a/P0 values were 14-1 mum. sec-1 and 0-29 respectively, whereas they were 31-9 mum. sec-1 and 0-44 in the N-EDL. 3. In the rat X-SOL there was shortening of the isometric twitch time to peak from 39-5 msec in the N-SOL to 19-7 msec and an increase in the intrinsic speed of shortening from 17-7 mum. sec-1 to 32-3 mum. sec-1, although over most of the force-velocity curve the X-SOL values were only slightly greater than those for N-SOL. The force-velocity data for the X-SOL muscles could not be fitted by Hill's equation. 4. The isometric and force-velocity results of the X-SOL of the rat suggested that the muscle contained a significant proportion of slow fibres. An examination of the motor unit characteristics of the N-FHL showed the presence of approximately 14% small, slow units. 5. It is concluded that there are no fundamental differences between the rat and the cat with regard to the effect of cross-reinnervation on hind-limb muscles. However, these, and previously published results, suggest that there may be important differences between heterologous muscles in the degree of influence that their respective motor nerves can exert on an alien muscle.


Properties of surface and junctional membranes of embryonic cells isolated from blastula stages of Xenopus laevis. 1. Some membrane properties of endoderm and mesoderm cells isolated from late blastula stages of Xenopus laevis have been examined using electrophysiological techniques. 2. Cells were isolated by treatment of whole embryos with Ca-free EDTA containing media, or mechanically by micro-dissection, and cultured in Ca-containing Holtfreter solution (60 mM-NaCl) or Ringer solution (120 mM-NaCl). 3. Membrane potentials lay between -6 and -84 mV; specific membrane resistances ranged from 500 to 29,000 omega cm2; there was no difference between EDTA isolated and mechanically isolated cells. 4. Relative and absolute cation and anion conductances varied from cell to cell. Some cells were anion impermeable; the cation conductance ranged from 35 to 300 mumho/cm2. 5. The resting potential of some cells was largely determined by the concentration gradient and membrane permeability of K ions. In other cells the potential was maintained either by some other ion or by an electrogenic pump. [K]i came to approximately 130 mM in Ringer solution (the value pertaining in the intact embryo) and similar to 60 mM in Holtfreter solution. 6. In most pairs and small clumps of cells ionic current spread from one cell to the next; some single cells and groups of cells were uncoupled from their neighbours. 7. The junctional resistance lay between 10(5) and 10(8) omega; it behaved as a linear resistor in most cell pairs studied. In three pairs the intercellular junction showed rectifying properites. 8. By the late blastula stage of development presumptive endoderm and mesoderm cells form a heterogeneous population with widely varying passive membrane properties. The significance of these findings is discussed in relation to current hypotheses for the formation of spatial patterns during differentiation.


Muscle load and constriction of the rabbit ear artery. This isolated, perfused ear artery of the rabbit has been used to examine the effect of alterations in muscle load on the construction of arteries. The equilibrium muscle load, taken as the difference in wall stress between the relaxed and constricted artery at the same external radius, was varied by changing the transmural pressure and by constricting the artery. 2. The equilibrium muscle load increased initially and then declined with decreasing external radius when the transmural pressure was kept constant. The maximum muscle load was reached when the relaxed external radius had been reduced by 11% at 80 mmHg and by 4-5% (relative to the radius at 80 mmHg) at 160 mmHg. 3. Arteries from young rabbits (3-6 months in age) which were partially constricted by adrenaline or spontaneous activity responded better to 60 sec of 4 Hz field stimulation at transmural pressures above 100 mmHg than did relaxed arteries. Neither field stimulation nor high concentrations of noradrenaline ( is greater than 800 ng/ml.) were able to constrict most arteries effectively at pressures above 160-170 mmHg unless partial constriction was present. The partial constriction reduced the load placed on the muscle by the same transmural pressure. Constrictio n during field stimulation was due largely to the release of neurotransmitter. 4. Ear arteries from young and older rabbits differed little in their ability to constrict against different transmural pressures. The one major difference was a lesser maximum constriction of arteries from older rabbits (18-24 months in age). However, arteries from older rabbits constricted well at the higher transmural pressures only because wall thickening largely compensated for a decreased ability of the muscle to develop active tension. 5. It is concluded that a decrease in internal radius to wall thickness ratio by either sufficient partial vasoconstriction or by wall thickening favours constriction of arteries because the load placed on the muscle by the same transmural pressure is reduced. Wall thickening may be an important compensatory reaction for deteriorating muscle contraction.


Spectral correlates of a quasi-stable depolarization in barnacle photoreceptor following red light. 1. Illumination of B. eburneus photoreceptors with intense red light produces a membrane depolarization that persists in darkness. This quasistable depolarization (latch-up) can be terminated with green light. The phenomenon was investigated with electrophysiological, spectrochemical, and microspectrophotometric techniques. 2. Latch-up was associated with a stable inward current in cells with the membrane potential voltage-clamped at the resting potential in darkness. The stable current could only be elicited at wave-lengths greater than 580 nm. 3. Light-induced current (LIC) was measured at various wave-lengths in dark-adapted photoreceptors with the membrane voltage-clamped to the resting potential. The minimum number of photons required to elicit a fixed amount of LIC occurred at 540 nm, indicating that the photoreceptor is maximally sensitive to this wave-length of light. The photoreceptor was also sensitive to wave-lengths in the near-U.V. region of the spectrum (380-420 nm). 4. Steady red adapting light reduced the magnitude of the LIC uniformly at all wave-lengths except in the near-U.V. region of the spectrum; sensitivity was reduced less in this region. 5. The spectrum for termination of the stable inward current following or during red light was shifted to the blue (peak about 510 nm) compared to the peak for LIC (peak about 540 nm). 6. Absorbance of single cells prepared under bright, red light decreased maximally at 480 nm following exposure to wave-lengths of light longer than 540 nm. 7. A pigment extract of 1000 barnacle ocelli prepared under dim, red light had a maximum absorbance change at 480 nm when bleached with blue-gree light. 8. There was no evidence in the latter two experiments of photointerconversion of pigments with absorbance maxima at 480 and 540 nm. Rather, the maximum absorption of the bleaching products seemed to occur at wave-lengths shorter than 420 nm. 9. Since latch-up induction occurs at wave-lengths longer than 580 nm, it may depend on the 540 pigment or on an undetected red absorbing pigment. 10. A photolabile pigment at 480 nm correlated most closely with termination of the stable inward current associated with latch-up.


Ionic mechanism of a quasi-stable depolarization in barnacle photoreceptor following red light. 1. The membrane mechanism of a quasi-stable membrane depolarization (latch-up) that persists in darkness following red light was examined in barnacle photoreceptor with micro-electrode techniques including voltage-clamp and Na+-sensitive micro-electrodes. 2. Current-voltage (I-V) relations of the membrane in darkness following red light (latch-up) and in darkness following termination of latch-up with green light, indicate that latch-up is associated with an increase of membrane conductance. 3. The latch-current (membrane current in darkness following red light minus membrane current in darkness following a gree flash that terminates latch-up) was inward at the resting potential, reversed sign at about +26mV (mean of six cells), and became outward at more positive membrance potentials. 4. Current-voltage relations of the membrane during green light (no latch-up) closely resembled those during latch-up. The light-induced current (LIC) elicited by green ligh (membrane current during the light flash minus membrane current in darkness following the light flash) was inward from the resting potential to +26mV (mean of six cells), then reversed sign and became outward. 5. The latch-current and LIC were both augmented in reduced Ca2+ solutions and decreased as Na-+ was reduced at a fixed Ca2+ concentration. 6. Both LIC and latch-current reversed sign at a more negative membrane potential (increment V equals 14mV) in solutions containing one quarter the normal amount of Na+. 7. The internal Na-+ activity (a-iNa) of a photoreceptor increased from about 10-18 mM upon illumination with long steps of intense red or white illumination. Five minutes in darkness after white light, a-iNa had recovered significantly, whereas a-iNa remained elecated following red illumination. 8. Latch-up seems to be a persistence in darkness of the same membrane mechanism that normally occurs during illumination; i.e. a conductance increase to Na+ ions. Ca2+ ions act primarily to suppress this current. There is evidence for a net Na+ influx during illumination that is sustained in darkness during latch-up.


The interactions of calcium with mpyxicola giant axons and a description in terms of a simple surface charge model. 1. Myxicola giant axons were examined under voltage clamp in solutions with [Ca2+] ranging from 2 to 200 mM. 2. The magnitude of the shifts in the Na and K conductance-voltage curves, as well as membrane rate constants, caused by changes IN [Ca22+] were comparable and consistent with a model in which there exists a negative surface charge density of -0.013 charges/A-2, but there is no significant binding of divalent cations to the external membrane surface. 3. There was no effect of equimolar substitution of magnesium for Ca on the positions of the conductance-voltage curves along the voltage axis, consistent with the above conclusion. 4. Ca2+ has no effect on the shape of the steady-state Na inactivation relation but simply causes a translation along the voltage axis. 5. It is concluded that a simple surface charge model in which divalent cations do not bind is adequate for Myxicola axons, and that there is no evidence to support a specific involvement of Ca with gating processes.


The antipyretic effect of indomethacin.

The antipyretic effect of indomethacin. 1. Several possible mechanisms of the antipyretic action of indomethacin administered cat. 2. Indomethacin did not decrease bacterial endotoxin-induced release of endogenous pyrogen in vivo. 3. Indomethacin (5-40 mug/kg) inhibited the pyrogenic effect of peripherally or centrally administered leucocytic progen. A dose of 10 mug/kg caused a parallel shift to the right of the log dose-response curve for I.V. leucocytic pyrogen and reduced the potency of the pyrogen at least 50%. 4. Incubation of leucocytic pyrogen with indomethacin did not alter its pyrogenic potency. 5. Indomethacin exerted only a slight non-dose-related hypothermic effect in afebrile animals. 6. Indomethacin (up to 1 mg/kg) did not diminish the hyperthermic response to intraventricular administration of prostaglandin E1. 7. This pattern of activity indicates that indomethacin acts centrally to inhibit an effect of leucocytic pyrogen.


The effect of sympathetic nerve stimulation on acid secretion, regional blood flows and oxygen usage by stomachs of anaesthetized cats. 1. Gastric acid secretion, and total gastric and mucosal blood flows (amidopyrine technique) were measured in anaesthetized cats. Oxygen contents of arterial and gastric venous blood were measured using an oximeter. 2. Splanchnic nerve stimulation (10 Hz) significantly reduced the acid output and total gastric and mucosal blood flows produced in response to maximal gastrin pentapeptide infusions. 3. The arterial haemoglobin concentration was significantly reduced during splanchnic nerve stimulation, and this is consistent with the hypothesis that the splanchnic nerve effect is directed against precapillary sphincters. 4. During the period of inhibition, gastric oxygen consumption and acid secretion were reduced to similar degrees. There was no significant change in oxygen extraction by the stomach. 5. It remains possible that the splanchnic nerves directly inhibit the parietal cell activity.


Contrast sensitivity of individual colour mechanisms of human vision. 1. Contrast sensitivity functions of isolated colour mechanisms were measured at spatial frequencies from 0-2 to 32 c/deg. The contrast sensitivity vs. spatial-frequency functions of the red (pi5) and green (pi4) mechanisms are similar, while the blue (pi3) mechanism has lower absolute sensitivity and lower resolving power. Isolation of a single mechanism never increases its maximum sensitivity. 2. The shape of the contrast sensitivity function of a colour mechanism is established within the mechanism. Little if any inhibitory interaction takes place among colour mechanisms. 3. Differences that have been reported between the sensitivities of the red and green mechanisms, as well as the apparent "supersensitivity" of the isolated green mechanism, may be artifacts that result from the extrapolation procedures that were used to estimate the absolute sensitivities of the colour mechanisms.


Innate and environmental factors in the development of the kitten's visual cortex. 1. This is a study of the receptive fields of 771 cells recorded in the visual cortex of twenty-five kittens reared normally or subjected to various kinds of visual deprivation or environmental manipulation. 2. Kittens deprived of patterned visual experience, by dark rearing or diffuse occlusion of the eyes, have a majority of cirtical neurones with little or no specificity for the orientation or axis of movement of visual stimuli. However, in such deprived animals, especially those younger than 3 weeks, there are a number of genuinely orientation selective cells. They are broadly "turned" (by adult standards), they are almost always of the simple type, are heavily dominated by one eye, and are found mainly in the deeper layers of the cortex, especially layer IV. 3...


The mechanical properties of oesophageal striated muscle in the cat and sheep. 1. A study has been made of the mechanical behaviour of isolated strips of cat and sheep oesophageal muscle. 2. At 37 degrees C, time to peak tension in an isometric twitch was about 80 ms in both muscles. Tetanic fusion frequency was 30 s-minus 1, twitch: tetanus ratio 0.4-0.47, and maximum velocity of shortening was 3 lengths. s-minus1. 3. The results are compared with the prperties of other muscles.


Descending inhibitory influences exerted by the brain stem upon the activities of dorsal horn lamina V cells induced by intra-arterial injection of bradykinin into the limbs. 1. In order to study descending influences of the brain stem upon the transmission of nociceptive messages at the spinal level, the activities of lumbar lamina V dorsal horn cells, induced by intra-arterial injection of brandykinin into the limbs, were recorded in unanaesthetized cats in both decerebrate and temporary spinal states (reversible cold block applied at the thoracic level). 2. In the decerebrate state, the intra-arterial injection of bradykinin had little or no effect. 3. During the reversible spinalization, the effects of bradykinin were revealed or considerably enhanced. As described in a previous study, in the C1-transected cat, three types of effects were encountered: excitatory, inhibiitory and mixed (inhibitory-excitatory). 4. These modifications observed after spinalization were generally associated with a large increase of the spontaneous firing rate. 5. These results emphasize, in the decerebrate cat, the importance of descending inhibitory controls exerted by the brain stem upon the transmission of nonciceptive messages at the spinal cord level.


Transport of electrolytes across the helicoidal colon of the new-born pig. 1. The Na, K, Cl and water content of faeces removed from different parts of the pig helicoidal colon were determined for 1-day-old and adult animals. Faecal Na, Cl and water content fell in both cases during passage of contents through the colon. K content increased in the distal colon of the adult pig. This did not occur in the 1-day-old animal. 2. The colon of the 1-day-old pig removed a larger proportion of water from its contents than did that of the adult. The absorption of both water and Cl was found to extend into the distal colon of the 1-day-old animal; little or no net absorption took place in this region in the adult. 3. Colons taken from new-born pigs maintained stable short-circuit currents of about 60-80 muA cm-2 with open-circuit voltages of about 10 mV. Similar values were found for proximal and mid regions of colons taken from 1-day-old, suckled animals. In the distal colon, however, both short-circuit current and open-circuit potential doubled after suckling. 4. Measurements of Na flux in vitro showed no regional difference at birth. The amount of Na absorbed, about 4.5 muequiv cm-2 h-1, was twice that predicted from the short-circuit current, supposing that to be due solely to the electrogenic transport of Na. 5. Colons taken from suckled pigs transported Na at double the rate found in the new-born animal. This applied to both the proximal region, where the short-circuit current remained constant, and the distal region, where the short-circuit was double that of the new-born. 6. Fluxes of Cl and K were also measured across the proximal colon of the one-day-old, suckled pig. There was a net absorption of Cl and secretion of K (1.3 and -0.05 muequiv cm-2 h-1 respectively). These fluxes, taken together with that for Na, could not wholly account for the short-circuit current measured across these preparations. 7. The pig colon seems well able to cope with both electrolyte and water absorption during the first 24 hr of post-natal life. Part of the absorbed sodium appears to follow a non-electrogenic, possibly pinocytotic, route, but the full ionic contribution to the measured short circuit current has still to be determined.


The differential effect of cooling on responses of cerebellar cortex. 1. Responses of the cerebellar cortex in anaesthetized cats were evoked by mossy fibre and/or climbing fibre inputs, and the effects of graded cooling of the cerebellar cortex were investigated. Cooling was applied either globally by flooding the exposed cortex with cooled Ringer Locke, or in later experiments locally be passing cooled fluid through a silver tube in contact with the cerebellar cortex. The cortical temperature was continuously monitored by a thermistor inserted to a depth of 0.5 mm close to the recording site. 2. In the granular layer the cooling caused a large increase in the diphasic P1N1 wave generated by the afferent mossy fibre volley. The waves generated by synaptic excitation and discharge of granule cells, N2P2, were not diminished until the temperature fell towards 20 degrees C. In contrast the N3 wave of the molecular layer was largest with cooling in the range of 35 to 25 degrees C, often several times larger than at 38 to 40 degrees C. Associated with the enhanced N3 wave there was an enhanced N4 wave, which indicates an increased discharge by Purkynĕ cells. 3. Climbing fibre inputs generate a negative field potential in the molecular layer due to the powerful excitation of Purkynĕ cells. In contrast to the N3 potential this climbing fibre wave was largest at the higher temperatures 35-40 degrees C and declined progressively with cooling, being usually suppressed at moderate coolings of 31-27 degrees C. Intracellular recording revealed that the diminution was due both to the elimination of all but the first impulses of the normal burst discharge of the climbing fibre impulses and to the diminution of the synaptic excitation of a single climbing fibre impulse. 4. It is shown that the negative potentials produced in the molecular layer by combinations of mossy fibre and climbing fibre inputs can be very effectively distinguished by this differential effect of cooling. 5. The effects of cooling even to a severe level are immediately recoverable on warming. Repeated cooling has no untoward effects and there is no sign of the hysteresis reported for the cuneate nucleus. 6. There is a discussion of the factors that could cause cooling to differentiate between the actions of the mossy fibre and climbing fibre impulses on Purkynĕ cells.


The effects of intra-ruminal loading with cold water on thermoregulatory behaviour in sheep. 1. Shorn sheep exposed to ambient termperatures of 5 degrees C soon learned to turn on infra-red heaters by placing their muzzles through a photoelectric beam, although before shearing they did not operate the heaters. 2. The duration of infra-red heating obtained decreased at higher ambient temperatures and at 25 degrees C very little heat was obtained. 3. When infra-red heaters totalling 900 or 1800 W were suspended above the sheep they turned on the 900 W heaters for almost exactly twice as long as they did the 1800 W heaters when exposed to 10 degrees C for 24 hr periods. 4. Loading the rumen with 1 l. water at 0-1 degree C produced an increment in the duration of infra-red heating obtained in a 1 hr period. At ambient temperatures of 0, 10 and 20 degrees C the increment observed after intraruminal loading with 2 l. water at 0-1 degree C was almost exactly double that obtained with a 1 l. loading. 5. Loading the rumen with 1 l. water at 0-1 degree C did not result in the sheep increasing the duration of infra-red heating obtained at ambient temperatures of 30 degrees C but a 2 l. loading was effective. At an ambient temperature of 40 degrees C the 2 l. load was ineffective.


Comparative study of the effects of propranolol and tetracaine on cation movements in resealed human red cell ghosts. 1. The effects of two positively charged local anaesthetic amines, tetracaine and propranolol, on cation permeability were studied in resealed human red cell ghosts prepared from metabolically depleted erythrocytes. 2. The K permeability was reduced by tetracaine but increased by propranolol. The effect of tetracaine was independent of extracellular Ca concentration but was raised to 2-5 x 10(-7) M. The effect of propranolol, which was enhanced when the external Ca concentration was raised, could be completely inhibited by lowering the internal free Ca to less than 10(-7) M. 3. Propranolol, but not tetracaine, increased the intracellular Ca ion concentration by releasing up to 20% of the membrane-bound Ca to the cell interior. This increase in intracellular Ca was sufficient to mediate the observed change in K permeability. 4. Tetracaine and propranolol reduced the Ca binding capacity of the ghost membrane by about 20 and 40% respectively. The Ca permeability was increased by propranolol and was  slightly reduced by tetracaine. 5. In high concentrations (2-7 mM) propranolol by itself moderately increased K and Na permeability, but supressed completely the Ca-induced increase in K permeability. Tetracaine in concentrations up to 4 mM enhanced the Ca-induced increase in K permeability. Higher concentrations of the drug caused lysis of the cells. 6. Maximally effective concentrations of tetracaine and propranolol inhibited the ATP-dependent Ca outward transport by 30 and 70% respectively. 7. The effects of tetracaine on K permeability were shared by the local anaesthetics prilocaine and lidocaine, those of propranolol were shared by practolol, a beta-adrenergic antagonist and tetraethylammonium, a ganglionic blocking agent. 8. It is suggested that the differences in the effects of tetracaine and propranolol on cation permeability reflect qualitatively different interactions of the two drugs with Ca binding sites on the inner surface of the membrane.


The interaction of adenosinetriphosphate and inorganic phosphate with the sodium pump in red cells. 1. An increase in the intracellular concentration of inorganic phosphate (Pi) reduces the rate of the Na:K exchange catalysed by the Na pump in red cells. The inhibitory effect of Pi is exerted on the maximum rate of flux, Pi having no appreciable effect on the apparent affinity of the Na pump for either internal Na or external K. The effect of Pi is exerted along a rectangular hyperbola which tends to zero as Pi tends to infinity and is half-maximal at about 17 mM internal Pi. 2. Pi does not modify the rate of Na:Na exchange catalysed by the Na pump. 3. A reduction in the intracellular concentration of ATP reduces the maximum rate of Na:K exchange having no effect on the apparent affinity for either internal Na or external K. 4. The effects of ATP and Pi are mutually independent. 5 The lack of effect of ATP and Pi on the apparent affinity for internal Na is compatible with the idea that the affinity of the inner sites of the Na pump remains constant during a pump cycle. 6. The lack of effect of ATP on the apparent affinity for external K and the independence between the effects of ATP and Pi are difficult to explain if the only effect of ATP were its combination at a phosphorylating site. 7. The apparent affinities for K and phosphate become independent of the concentration of ATP, if it is assumed that in our experimental range the phosphorylating site is fully saturated with ATP, the rate of pumping being controlled by the state of occupation of a second non-phosphorylating site whose affinity for ATP is much lower. 8. The lack of effect of Pi on the apparent affinity for external K seems to indicate that during Na:K exchange the conformations of the pump that predominate are endowed with a reactivity towards inorganic phosphate and have the same high affinity for K in both their phospho and their dephospho states. 9. The kinetic behaviour of the Na pump in regard to its interactions with inner and outer cations, ATP and Pi seems to indicate that, in contrast with what happens with soluble allosteric proteins, in the active transport system ligand-induced changes in the reactivity are more important than ligand-induced changes in affinity. In this respect therefore the Na pump behaves as an allosteric 'V system'.


The effects of vasectomy on postoperative psychological adjustment and self-concept. Twenty men undergoing vasectomies completed the Tennessee Self Concept Scale shortly before the operation and again at 6- and 18-month postoperative follow-up periods. Twenty nonvasectomy comparison subjects completed the test at the same points in time. Results indicated that vasectomy adversely affects psychological adjustment, and this effect fluctuates over time as a function of preoperative level of defensiveness. In contrast, vasectomy was not found to effect changes in self-concept.


Relationship of a measure of selfqactualization to religious participation. This study examined the hypothesis that self-actualization is negatively associated with reported frequency of active involvement in religious activities. A group of 63 male undergraduates enrolled in a Catholic coeducational institution indicated the extent of their involvement in religious activities and completed Shostrom's Personal Orientation Inventory (POI), a comprehensive measure of self-actualization. Results indicated substantial support for the hypothesis. Nine of the 12 Shostrom POI subscales were significantly correlated with the religious participation index in the predicted direction. It was suggested that self-actualizing students construe involvement in religious activities as being detrimental to thier psychosocial development.


The effects of warm-up activities on small group divergent problem-solving with young children. This study investigated the effects of warm-up activities on divergent production by young children in small group problem-solving settings, hypothesizing that game-like activities designed to develop a psychological set for creative thinking previous to group problem-solving will actually facilitate idea production. One hundred five first-grade children were randomly assigned to four conditions with number and sex equated: three differing warm-up treatments (two task-related and one not) and one condition of no warm-up for 20 minutes previous to a small group administration of an activity from the Torrance Tests of Creative Thinking. Scores obtained for fluency, flexibility, and originality showed significant treatment effects on originality, with flexibility approaching significance, for the two task-related warm-up treatments. It was concluded that these types of activities positively influence a psychological set for divergent production.


Is there an astrological effect on personality? This is a brief comment questioning Pellegrini's finding of marked correlations between the astrological sun sign of birth and the Femininity scale of the California Psychological Inventory.


Birthdate psychology: a new look at some old data. This brief note deals with the development of alternative perspectives on the provocative, and as yet unexplained result of an earlier study in which groups of people born under different astrological zodiac signs were found to differ markedly in their scores on the California Psychological Inventory (CPI) scale described as a measure of "Femininity." Attention is focused on (a) discrepancies between the observed pattern of high and low scores on the CPI Femininity scale, and classification of sun signs as "masculine" or "feminine" by astrologers; (b) the trend in the data indicating that the six sun sign categories for which the highest scores were obtained on the Femininity scale correspond to birthdates running continuously from July 24 to January 20, while the six sun sign categories for which the lowest scores were obtained on that scale correspond to birthdates running continuously from January 21 to July 23; and (c) speculative consideration of the kinds of climatic, dietary, and/or cyclical geomagnetic events that might affect reproduction and prenatal and/or neonatal development in such a way as to influence adult personality.


Self-esteem and internal versus external control among black youth in a summer aviation program. Changes in self-esteem and belief in internal versus external control of reinforcement (skill versus chance) were investigated among 24 black male and female youngsters, aged 12 through 19, and from diverse backgrounds and geographical locations. Age, socioeconomic status, geographical location, and achievement in flight training were varied. Results showed significant gains in self-esteem by Ss under 16 years of age (p smaller than .05) and Ss from middle income families (p smaller than .005). There was no significant change in belief in internal versus external control among any of the subgroups.


Pupillary dilation as a measure of sexual arousal. A reply to Hamel. A comment is presented on a report dealing with pupillary dilation as a measure of sexual interest. Objections are made concerning the use of an earlier paper by the author as a "straw man," and caution pertaining to traditional methodology is offered.


Phobic response factors from the fear survey schedule. A Phobic Response Scale was factored from responses to the Fear Survey Schedule. Subjects were 137 male and 168 female college students. A six factor solution extracted 41.78% of the trace. The factors were as follows: I (Hostile-Dependence), II(Body assult), III (Developmental Fears), IV (Performance and Evaluation), V (Death Evasion), and VI (Nuisance Animals). An analysis of sex differences by item and scale generally supported and extended previous research. Some conceptual ties were made by scale to traditional phobic response styles and diagnostic categories.


Physical attractiveness, happiness, neuroticism, and self-esteem. The hypotheses that physical attractiveness is positively correlated with happiness, psychological health, and self-esteem was tested with 211 men and women undergraduates. Physical attractiveness was measured by judges' ratings, while happiness, psychological health (neuroticism), and self-esteem were measured by self-report inventories. Physical attractiveness was found to correlate positively with happiness (r equals .37), negatively with neuroticism (r equals minus.22), and positively with self-esteem (r equals .24) for women but not for men (corresponding rs equals .09, .03, and minus.04, respectively). These results were accounted for by the suggestion that physical attractiveness "buys" more for women than for men, and the most prominent outcomes obtained by physical attractiveness--friends and dates--are of greater value to women undergraduates than men. The superior outcomes obtained by the attractive women made them happy, psychologically healthy, and proud of themselves.


Evidence for the generality of reminiscence as a function of extraversion and neuroticism. The study was conducted in order to determine whether magnitude of reminiscence would vary consistently across different motor tasks as a function of personality factors. Twenty-eight male and female college students were all given eight trials on both the inverted alphabet printing and pursuit rotor tasks. Personality measures of extraversion and neuroticism were obtained on all Ss by means of the Eysenck Personality Inventory. Results indicated that extraverts showed significantly more reminiscence than introverts on both tasks. Data argued against a "task-specific" account of reminiscence and suggested rather that reminiscence effects are characteristic of the individual.


Personality correlates of verbal conflict resolution. The scores on 11 Guilford-Zimmerman Temperament Survey scales and the Taylor Manifest Anxiety Scale of 80 male and female college students were related in four multiple regression analyses to verbal conflict resolution times for approach-approach, avoidance-avoidance, double approach-avoidance, and average time for all conflicts. The multiple correlations were not significant; however, an analysis of 56 Ss who gave more than four question-mark responses on any one Guilford-Zimmerman factor produced three significant multiple correlations. A tentative personality profile of the slow conflict resolver emerged: low score on the Personal Relations and Socialibility scales. A subtle subject-experimenter interaction was proposed as an explanation of the results.


An intergrative factor analysis of leadership measures and theories. Since the instruments for measuring most of the current leadership models have never been reconciled, it is important that the relationships between them be clearly understood before assumptions of similarity are made. A sample of 103 male working students were given a battery of tests measuring leadership orientations. The tests included role preference and role pressure measures from Sweney's Response to Power Model, the California F Scale, Fiedler's Least Preferred Co-Worker Scale and Assumed Similarity Between Opposites Scale, Costley and Downey's six scales to measure McGregor's "Theory X" and "Theory Y" constructs, modified scales for the Blake and Mouton Managerial Grid, and relevant scales from the 16 PF. The results were intercorrelated and yielded 11 varimax factors based upon a Guttman criterion, as follows: Authoritarian Role Preferance, Authoritarian Role Pressure, Equalitarian Role Preferance, Equalitarian Role Pressure, Balanced Manager, People Oriented Manager, Assumed Similarity Between Opposites, Contemptuous Indulgence, Supportive Values, People Tolerance, and Organizational Tolerance. The instruments measuring authoritarianism loaded the first factor in the right direction, but most of them had their primary loadings elsewhere, suggesting greater conceptual complexity to this area than previously recognized.


Relations between behavioral characteristics of infants, their mothers' behaviors, and performance on the Bayley Mental and Motor Scales. Bayley Mental scores were significantly related to several concurrent ratings of infant and maternal testroom behavior when firstborn black male infants were 14 months (N equals 49), 18 months (N equals 34), and 22 months of age ( equals 32). With increasing age, social responsiveness played a relatively less important role in successful performance, while object responsiveness became increasingly important. Bayley Motor scores were related to many fewer ratings than the Mental scores. Gross Muscle Coordination was related to performance at all three ages, and Energy ratings at two of the three ages. For both the Mental and Motor scores, fewer relationships were observed at the 18-month testings as compared to the 14 and 22-month testings. By 22 months, infants scoring higher on the Bayley Mental scale had mothers who were more highly involved with their child's achievement as judged by testroom behaviors.


Exogenous stages of Isospora serini (Aragão)and Isospora canaria sp. n. in the canary (Serinus canarius Linnaeus). Exogenous stages of Isospora serini (Aragao) and Isospora canaria sp. n. from the canary (Serinus canarius Linnaeus) are described. Oocytes of I. serini are spheroid and average 19.2 times 20.1 mum, while those of I. canaria are larger, more ellipsoid, and average 21.8 times 24.6 mum. No oocyst residuum is present and the oocyst walls of both species are colorless, transparent, and single layered. Sporocysts average 9.4 times 15.2 mum for I. serini and 11.5 times 18.1 mum for I. canaria. The I. canaria sporocyst has a substiedal body, but none was found in I. serini sporocysts. Both species have a spherical sporocyst residuum; this was obscured in the I. serini sporocyst by scattered granules. Living sporozoites of I. canaria average 3.6 times 16.9 mum and have 1 to 3 refractile globules; those of I. serini have 2 globules and average 2.8 times 12.6 mum. A disseminated infection of the mononuclear phagocytes results from administration of I. serini while I. canaria oocysts give rise to a typical coccidian infection restricted to the intestinal epithelium. Asexual stages of I. serini in macrophages are indistinguishable from parasites previously called avian Toxoplasma, Atoxoplasma, and Lankesterella.


The immobilization antigen of Paramecium aurelia is a single polypeptide chain. The immobilization antigen (i-antigen) fraction of Paramecium aurelia syngen 4 is shown to contain a protease that is activated by mercaptoethaneol. After the protease has been heat-inactivated, the molecular weight of the i-antigen (similar to 250,000 daltons) cannot be decreased by mercaptoethanol treatment. It is demonstrated that the i-antigen is a single polypeptide chain. Reasons are also given why low molecular weight subunits were previously reported by other authors.


[Arteriography in renal metastases from solid tumors (excluding lymphomas). Study of 3 cases and review of the literature]. Three cases of arteriography of renal metastasis of solid tumors are presented. Twice the primitive cancer was bronchial, once laryngeal. There is not other clinical metastasis at the time of arteriography. A general revue of the 19 observations of the litterature is donemthe indication of the arteriography is justified if the primary tumor is not known or if there is not other metastasis. On the cortrary if they are diffused, the indications of this angiography are obviously very limited. In six cases, one can see, as in our observation, stretched thin, encased arteries with a lacune at the nephrographic time. In six other, at these images, are associated rare flecks and neovascularisations; Theses radiological syndromes seem to us characteristic. More rarely the angiography may be normal (3 cases) or look like a primitive renal tumor (3 cases). We must say, however, that nearly all the observations have anatomicaly a renal tumor. The other types of renal metastasis are not well known angiographycally.


[Angiographic diagnosis of lesions of Winslow's lobe of the pancreas (author's transl)]. Winslow's lobe, the postero-inferior lobe of the head of the pancreas, gives rise to special angiographic appearances owing to its posterior position in relation to the axis of the superior mesenteric artery. It displaces the superior mesenteric artery laterally and forwards, and may also obstruct the vein. In 12 cases of pancreatitis, these signs were usually due to a pseudo-cyst of this lobe of the pancreas, the angiographic discovery of which provided greater accuracy in diagnosis. In 4 cases of carcinoma of the pancreas, there was also irregular stenosis of the first few jejunal arteries, the diagnostic interest of which is important.


[Radiological study of congenital mono and bicuspid aortic valves (author's transl)]. Bicuspid aortic valves are much more common than monocuspid valves and diagnosed by A. P. aortography and, above all, lateral views. One may distinguish the true bicuspid valves which include two Valsalva sinuses, often asymmetrical, and bicuspid valves whith a supplementary raphe, the commonest type, in which on angiography, one may distinguish three Valsalva sinuses, one of which is larger than the two others. These cases of bicuspid aortic valve may be associated with other malformations of the aorta or may occur alone. In the latter case, the main risks are aortic valvular stenosis or aortic incompetence.


[Familial reno-vascular hypertension (author's transl)]. The authors report a case of hypertension due to dysplasia of the renal arteries in a young man, and found the same disease in siblings. Two sisters and one brother also had renal hypertension, whereas the other relatives were unaffected. Two similar cases found in the world literature, did not permit the authors to determine the cause of this disease. This case is reported in order to stimulate research and the discovery of new cases.


[A case of parieto-pulmonary acquired shunt presenting with hemoptysis (author's transl)]. The authors report the case of a 52 year old man with arteriovenous shunt developing from the 7th left intercostal artery, revealed by hemoptysis and proved by intercostal selective arteriography. The patient had a past history of serofibrinous pleurity 29 years previously and had undergone paracentesis at this level. The origin of this shunt is then discussed.


[The capsule sign in severe hydronephrosis (author's transl)]. In severe obstructive disease of the kidney, with major distension of the intrarenal collecting ducts and marked thinning of the parenchyma, intravenous urography with high doses of contrast medium may reveal, almost pathognomic nephrographic abnormalities, such as, the dense capsule appearance, or septal appearances. The diagnostic value of these radiological appearances is all the greater in these very advanced cases of hydronephrosis, opacification of the excretory ducts can often not be obtained.


[Roentgenographic aspects of subcapsular renal hematomas (author's transl)]. About four cases, the authors exhibit roentgenographic features of subcapsular hematomas. They particularly emphasize the interest of nephrotomography and angiography two provide the typical signs; i.e.: flattening of the lacteral border of the renal parenchyma, absence of acute edges between normal renal outline and flattened portion, and at last, displaced capsular artery and/or renal capsule itself. Between flattening of kidney and capsular artery or capsule, one may individualize a mass of soft tissue density, convex or biconvex, corresponding to the hematomas. Particular attention is required concerning differential diagnosis with renal cyst, and possibility of a small neoplasm, sometimes indetectable at angiography, as a cause of "spontaneous" subcapsular hematoma.